Ion implanter and ion implantation method

Abstract

To provide an ion implanter or the like capable of shortening a time for which workpieces stay in a beam non-irradiation range.SOLUTION: An ion implantation method includes the steps of: (a) moving a wafer adjusted to have a first implantation angle with respect to an ion beam from a beam irradiation range in which the wafer is irradiated with the ion beam toward a beam non-irradiation range which is adjacent to at least one end of the beam irradiation range and in which the wafer is not irradiated with the ion beam; (b) starting a change of the wafer from the first implantation angle to a second implantation angle while the wafer having the first implantation angle is moved within the beam non-irradiation range to which the wafer is moved from the beam irradiation range; (c-1) reversing a movement direction of the wafer at an end of the beam non-irradiation range and moving the wafer toward the beam irradiation range; and (c-2) completing the change of the wafer from the first implantation angle to the second implantation angle while the wafer is moved within the beam non-irradiation range before the wafer is returned to the beam irradiation range.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to an ion implantation apparatus and an ion implantation method. [Background technology]

[0002] Patent Document 1 discloses an ion implantation device that irradiates the same reciprocating wafer with ion beams at different implantation angles multiple times. When the ion beam irradiation direction is approximately constant, the implantation angle of the ion beam with respect to the wafer is determined, for example, by a combination of the wafer's twist angle (rotation angle) and tilt angle (tilt angle). Since the ends of the wafer's reciprocating movement range are non-beam irradiation ranges where the wafer is not irradiated with the ion beam, by changing the wafer's twist angle and / or tilt angle when reversing the wafer's movement direction at the end of the reciprocating movement range, which is also the end of the non-beam irradiation range, the implantation angle can be changed without exposing the wafer to the ion beam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-69055 Summary of the Invention [Problem to be solved by the invention]

[0004] In the ion implantation apparatus of Patent Document 1, the twist angle and / or tilt angle of the wafer must be changed when the wafer reverses its movement direction at the end of its reciprocating movement range (non-beam irradiation range), which results in the wafer spending a long time in the non-beam irradiation range.As the ion beam is not irradiated onto the wafer in the non-beam irradiation range, there is a risk that the efficiency of the ion implantation process will decrease as a result.

[0005] The present invention has been made in view of the above circumstances, and one of its exemplary objects is to provide an ion implantation apparatus and the like that can shorten the residence time of a workpiece in a non-beam irradiated area when changing the implantation angle of the workpiece relative to the ion beam. [Means for solving the problem]

[0006] In order to solve the above problems, an ion implantation apparatus according to one embodiment of the present invention comprises: a support mechanism for supporting a workpiece to be irradiated with an ion beam; an implantation angle adjustment mechanism capable of adjusting the implantation angle of the workpiece supported by the support mechanism relative to the ion beam; a drive mechanism for reciprocating the support mechanism in a direction intersecting the ion beam, the reciprocating range of the drive mechanism including a beam irradiation range in which the ion beam is irradiated onto at least a portion of the workpiece; and a non-beam irradiation range adjacent to at least one end of the beam irradiation range in which the workpiece is not irradiated with the ion beam; a processor for controlling the implantation angle adjustment mechanism and the drive mechanism; and a memory in which a program is stored. Based on the program, the processor executes the following steps: (a) moving the workpiece, which has been adjusted to a first implantation angle by the implantation angle adjustment mechanism, from the beam irradiation range toward the non-beam irradiation range by the drive mechanism; (b) following step (a), starting to change the implantation angle of the workpiece from the first implantation angle to a second implantation angle different from the first implantation angle by the implantation angle adjustment mechanism while the workpiece is moving within the non-beam irradiation range after being moved from the beam irradiation range to the non-beam irradiation range by the drive mechanism; (c-1) following step (b), reversing the movement direction of the workpiece at the end of the non-beam irradiation range by the drive mechanism to move it toward the beam irradiation range; and (c-2) following step (b), completing to change the implantation angle of the workpiece from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism while the workpiece is moving within the non-beam irradiation range before being moved from the non-beam irradiation range back to the beam irradiation range by the drive mechanism.

[0007] In this embodiment, after the workpiece moves from the beam irradiation range to the non-beam irradiation range at the first implantation angle, the change to the second implantation angle begins before the workpiece reaches the reversal end of the movement direction of the non-beam irradiation range (hereinafter referred to as the reversal end for short) of the non-beam irradiation range. The change to the second implantation angle is completed while the workpiece is moving within the non-beam irradiation range before returning from the non-beam irradiation range to the beam irradiation range. In this way, the movement of the workpiece within the non-beam irradiation range and the change of the implantation angle are performed in parallel, thereby shortening the time the workpiece spends in the non-beam irradiation range. As a result, the time the workpiece spends in the beam irradiation range where the ion beam is irradiated becomes relatively longer, thereby improving the efficiency of the ion implantation process.

[0008] Another aspect of the present invention is an ion implantation method, comprising: (a) moving a workpiece, adjusted to a first implantation angle with respect to an ion beam, from a beam irradiation range, in which at least a portion of the workpiece is irradiated with the ion beam, toward a non-beam irradiation range adjacent to at least one end of the beam irradiation range, in which the workpiece is not irradiated with the ion beam; (b) subsequent to step (a), starting to change the first implantation angle of the workpiece to a second implantation angle different from the first implantation angle while the workpiece is moving within the non-beam irradiation range after moving from the beam irradiation range to the non-beam irradiation range; (c-1) subsequent to step (b), reversing the movement direction of the workpiece at the end of the non-beam irradiation range and moving it toward the beam irradiation range; and (c-2) subsequent to step (b), completing the change of the first implantation angle of the workpiece to the second implantation angle while the workpiece is moving within the non-beam irradiation range before returning from the non-beam irradiation range to the beam irradiation range.

[0009] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present invention. [Effects of the Invention]

[0010] According to an aspect of the present invention, it is possible to reduce the time the workpiece stays in a non-beam irradiated area when changing the implantation angle of the workpiece with respect to the ion beam. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a top view showing a schematic configuration of an ion implantation apparatus. [Figure 2] 1 is a side view showing a schematic configuration of an ion implantation apparatus. [Figure 3] 10A and 10B show schematic diagrams of an ion beam deflected by an electric field from a direction in which irradiation is possible to a direction in which irradiation is not possible. [Figure 4] 10A and 10B show schematic diagrams of an ion beam deflected by a magnetic field from a direction in which irradiation is possible to a direction in which irradiation is not possible. [Figure 5] 10 shows a modified example of the beam blocking mechanism. [Figure 6] 10 shows a modified example of the beam blocking mechanism. [Figure 7] 10 shows a modified example of the beam blocking mechanism. [Figure 8] 10 shows a modified example of the beam blocking mechanism. [Figure 9] 10 shows a modified example of the beam blocking mechanism. [Figure 10] FIG. 2 is a front view showing a schematic configuration inside the implantation processing chamber. [Figure 11] FIG. 10 is a top view schematically showing the inside of the implantation processing chamber during the implantation step. [Figure 12] FIG. 10 is a top view schematically showing the inside of the implantation processing chamber in the preparation step. [Figure 13] FIG. 10 is a top view schematically showing the inside of the implantation processing chamber during the calibration process. [Figure 14] 1A-1C are schematic diagrams illustrating an implantation process with a non-zero tilt angle. [Figure 15] 3A and 3B are diagrams illustrating changes in the twist angle caused by the twist angle adjustment mechanism. [Figure 16] 10A-10C show schematic diagrams of non-zero tilt angle implantation processes with different twist angles; [Figure 17] FIG. 1 is a functional block diagram of an ion implantation apparatus. [Figure 18]2 is a timing chart schematically showing a basic operation in an implantation process of an ion implantation device. [Figure 19] An example in which a beam scanning function and a beam deflection function are realized by a single beam scanning device is shown schematically. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description or drawings, identical or equivalent components, parts, and processes are designated by the same reference numerals, and redundant explanations will be omitted. The scale and shape of each part shown in the drawings are set for convenience to facilitate explanation, and should not be interpreted as limiting unless otherwise specified. The embodiments are merely examples and do not limit the scope of the present invention in any way. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0013] FIG. 1 is a top view showing a schematic configuration of an ion implantation apparatus 10 according to an embodiment of the present invention, and FIG. 2 is a side view showing a schematic configuration of the ion implantation apparatus 10. The ion implantation apparatus 10 is an apparatus that performs ion implantation processing on the surface of a workpiece W. The workpiece W is, for example, a semiconductor wafer or a substrate for a display device. In this specification, the workpiece W is also referred to as a wafer W for convenience, but this is not intended to limit the target of the ion implantation processing to a specific object or material such as a semiconductor wafer.

[0014] The ion implantation apparatus 10 reciprocates the ion beam in one direction (hereinafter also referred to as the scanning direction, beam scanning direction, or beam movement direction) and reciprocates the wafer W in a direction perpendicular to the scanning direction (hereinafter also referred to as the reciprocating movement direction, reciprocating movement direction, or wafer movement direction), thereby irradiating the ion beam over the entire surface to be processed of the wafer W. In this specification, the direction of travel of the ion beam along the designed beamline A (hereinafter also referred to as the beam traveling direction) is defined as the z direction, and a plane perpendicular to the z direction is defined as the xy plane. The scanning direction (beam movement direction) of the ion beam when scanning the workpiece W with the ion beam is defined as the x direction, and the y direction perpendicular to the z and x directions is defined as the wafer movement direction. In this manner, the reciprocating scan of the ion beam is performed in the x direction, and the reciprocating movement of the wafer W is performed in the y direction.

[0015] The ion implantation apparatus 10 includes an ion generator 12, a beamline device 14, an implantation processing chamber 16, and a wafer transport device 18. The ion generator 12 supplies an ion beam to the beamline device 14. The beamline device 14 transports the ion beam supplied from the ion generator 12 to the implantation processing chamber 16. A wafer W to be implanted with ions is accommodated in the implantation processing chamber 16, and an ion implantation process is performed by irradiating the wafer W with the ion beam supplied from the beamline device 14. The wafer transport device 18, which serves as a transport device, loads unprocessed wafers before ion implantation processing into the implantation processing chamber 16 and loads processed wafers after ion implantation processing out of the implantation processing chamber 16. Although not shown, the ion implantation apparatus 10 is also provided with a vacuum pumping system for providing a desired vacuum environment for the ion generator 12, the beamline device 14, the implantation processing chamber 16, and the wafer transport device 18.

[0016] The beamline device 14 includes, in order from the upstream side of the beamline A, a mass analysis unit 20, a beam park device 24, a beam shaping unit 30, a beam scanning device 32, a beam collimator 34, and an angular energy filter (AEF) 36. Note that the upstream side of the beamline A refers to the side closer to the ion generator 12, and the downstream side of the beamline A refers to the side closer to the implantation processing chamber 16 (or beam stopper 46).

[0017] The mass analysis unit 20, which is provided downstream of the ion generator 12, selects or extracts, through mass analysis, desired ion species to be used in the ion implantation process from the ion beam generated by the ion generator 12. The mass analysis unit 20 includes a mass analysis magnet 21, a mass analysis lens 22, and a mass analysis slit 23.

[0018] The mass analysis magnet 21 applies a magnetic field to the ion beam extracted from the ion generator 12, deflecting the ion beam into different trajectories depending on the value of the ion mass-to-charge ratio M=m / q (m is mass, q is charge). For example, the mass analysis magnet 21 applies a magnetic field in the -y direction to the ion beam to deflect the ion beam in the x direction. The magnetic field strength of the mass analysis magnet 21 is adjusted so that ion species having a desired mass-to-charge ratio M can pass through the downstream mass analysis slit 23.

[0019] The mass analysis lens 22 is provided downstream of the mass analysis magnet 21 (and upstream of the mass analysis slit 23) and adjusts the converging / diverging force on the ion beam (or the degree of convergence / divergence of the ion beam). The mass analysis lens 22 adjusts the focusing position of the ion beam passing through the mass analysis slit 23 in the beam traveling direction (z direction), and adjusts the mass resolution M / dM of the mass analysis unit 20. Note that the mass analysis lens 22 does not necessarily have to be provided in the mass analysis unit 20.

[0020] The mass analysis slit 23 is provided at a downstream position away from the mass analysis lens 22. The mass analysis slit 23 has a rectangular opening 23a that is relatively short in width in the x direction and relatively long in height in the y direction. Because the width direction (x direction) of the opening 23a coincides with the direction of beam deflection (x direction) by the mass analysis magnet 21, it is the width (dimension in the x direction) of the opening 23a that primarily contributes to the selection of the desired ion species according to the mass-to-charge ratio M in the mass analysis slit 23.

[0021] The mass analysis slit 23 may have a variable slit width (width of the opening 23a) to adjust the mass resolution. For example, the mass analysis slit 23 may be configured with two shields that are relatively movable in the slit width direction (x direction), and the slit width may be adjusted by changing the distance between the two shields in the slit width direction. Furthermore, the slit width of the mass analysis slit 23 may be changed by switching between multiple slits with different slit widths.

[0022] The beam park device 24 constitutes a beam deflection device that deflects the ion beam by at least one of an electric field and a magnetic field. Specifically, the beam park device 24 can be switched between an irradiation enabled state in which the ion beam is directed in an irradiation enabled direction in which it can be irradiated onto the wafer W, and an irradiation disabled state in which the ion beam is directed in an irradiation disabled direction in which it cannot be irradiated onto the wafer W. In the example of Figure 2, an arrow pointing into the opening 23a of the mass analysis slit 23 indicates the irradiation enabled direction, and an arrow pointing toward the beam dump 26 outside the opening 23a of the mass analysis slit 23 indicates the irradiation disabled direction. Here, the mass analysis slit 23 is a slit that passes at least a part of the ion beam directed in the irradiation enabled direction, and is provided between the beam park device 24 as a beam deflection device and a wafer holding device 52 (Figure 2) as a holding device, which will be described later.

[0023] When the beam park device 24 is in an inoperative state, it temporarily evacuates the ion beam from the beam line A and uses the beam dump 26 to block the ion beam heading toward the downstream implantation processing chamber 16 (or wafer W). That is, the ion beam heading toward the inoperative direction collides with the beam dump 26 outside the mass analysis slit 23 and is blocked. The beam park device 24 can be placed anywhere on the beam line A, but in the illustrated example, it is placed between the mass analysis lens 22 and the mass analysis slit 23. As described above, a certain distance or more is required between the mass analysis lens 22 and the mass analysis slit 23, so placing the beam park device 24 there between them allows for efficient use of space. As a result, the beam line A can be shortened and the entire ion implantation apparatus 10 can be made smaller than if the beam park device 24 were placed elsewhere.

[0024] 1 and 2 constitutes a type of beam deflection device that deflects an ion beam by an electric field. This beam park device 24 includes a pair of park electrodes 25 (25a, 25b) and a beam dump 26. The pair of park electrodes 25a, 25b face each other in the y direction across the beamline A. The beam park device 24 switches the ion beam between an irradiable direction and an inirradiable direction in response to a change in the electric field in the y direction caused by a change in the voltage applied to the pair of park electrodes 25a, 25b.

[0025] 2, when no voltage is applied to the pair of park electrodes 25a, 25b (i.e., when the voltage is approximately zero), the beam of the desired ion species used in the ion implantation process is not deflected but travels straight in the irradiation direction and passes through the opening 23a of the mass analysis slit 23, thereby achieving an irradiation-enabled state. On the other hand, when a voltage is applied to the pair of park electrodes 25a, 25b (i.e., when the voltage is a significant non-zero value), the beam of the desired ion species used in the ion implantation process is deflected in the -y direction, travels in the non-irradiation direction, collides with the beam dump 26 outside the opening 23a of the mass analysis slit 23, and is blocked, thereby achieving an irradiation-disabled state.

[0026] In the above example, when the ion beam is not deflected because no voltage is applied to the pair of park electrodes 25a, 25b, the ion beam advances in the irradiation direction, and when the ion beam is deflected because a voltage is applied to the pair of park electrodes 25a, 25b, the ion beam advances in the non-irradiation direction. However, it is also possible to configure the ion beam to advance in the non-irradiation direction when not deflected and to advance in the irradiation direction when deflected. In this case, for example, a beam dump 26 may be provided at the position of the opening 23a of the mass analysis slit 23 in Fig. 2, and the opening 23a of the mass analysis slit 23 may be provided at the position of the beam dump 26 in Fig. 2. In this case, the configuration downstream of the opening 23a is also provided on the beamline A of the (deflected) ion beam passing through the opening 23a.

[0027] Furthermore, the ion beam traveling in the irradiation direction and the ion beam traveling in the non-irradiation direction may be deflected by different voltages applied to the pair of park electrodes 25 a, 25 b. For example, if the irradiation direction (the direction in which the opening 23 a of the mass analysis slit 23 is located) forms a first deflection angle Θ1 with respect to the incident direction of the ion beam into the beam park device 24, and the non-irradiation direction (the direction in which the beam dump 26 is located) forms a second deflection angle Θ2 that is significantly different from the first deflection angle Θ1 with respect to the incident direction of the ion beam into the beam park device 24, the traveling direction of the beam of a desired ion species can be switched between the irradiation direction and the non-irradiation direction by switching the voltage applied to the pair of park electrodes 25 a, 25 b between a first voltage V1 that realizes the first deflection angle Θ1 and a second voltage V2 (≠V1) that realizes the second deflection angle Θ2.

[0028] As described above, the pair of park electrodes 25a, 25b face each other in the y direction, which is perpendicular to the beam deflection direction (x direction) of mass analysis magnet 21. Therefore, the deflection voltage in the y direction applied to the pair of park electrodes 25a, 25b does not interfere with the selection of desired ion species according to the mass-to-charge ratio M performed by mass analysis magnet 21 along the x direction.

[0029] 2, the first park electrode 25a is arranged above the beamline A in the direction of gravity (the opposing direction of the first park electrode 25a and the second park electrode 25b), and the second park electrode 25b is arranged below the beamline A in the direction of gravity. The beam dump 26 provided downstream of the first park electrode 25a and the second park electrode 25b is arranged below the beamline A in the direction of gravity and below the opening 23a of the mass analysis slit 23 in the direction of gravity. The beam dump 26 is, for example, a wall-like portion in which the opening 23a of the mass analysis slit 23 is not formed. The beam dump 26 may be configured separately from the mass analysis slit 23.

[0030] FIG. 3 schematically illustrates an ion beam IB deflected from the irradiation direction D1 (or beam line A) to the non-irradiation direction D2 by a voltage applied to a pair of park electrodes 25a, 25b. The deflection angle θ of the ion beam IB shown in the figure is the angle between the irradiation direction D1 and the non-irradiation direction D2. Here, the ion beam IB bends as it travels between the pair of park electrodes 25a, 25b where the electric field acts and in the region nearby. The deflection angle θ of the ion beam IB is defined as the angle between the irradiation direction D1, in which the ion beam IB traveled straight before bending, and the non-irradiation direction D2, in which the ion beam IB travels straight after bending. If the deflection angle θ is too small, there is a risk that part of the ion beam IB will enter the opening 23a of the mass analysis slit 23. If the deflection angle θ is too large, the mass analysis slit 23 constituting the beam dump 26 will become too large. As a result of the inventor's investigation, it has been found that the deflection angle θ between the irradiation possible direction D1 and the irradiation impossible direction D2 is preferably between 2 and 60 degrees, more preferably between 3 and 45 degrees, and even more preferably between 5 and 30 degrees.

[0031] Fig. 4 shows a schematic diagram of an ion beam IB deflected from an irradiation possible direction D1 (or beam line A) to a non-irradiation possible direction D2 by a magnetic field applied between a pair of magnetic poles 25c, 25d. While the beam park device 24 shown in Figs. 1 to 3 constitutes a type of beam deflection device that deflects an ion beam by an electric field, the beam park device 24 according to the modified example of Fig. 4 constitutes a type of beam deflection device that deflects an ion beam by a magnetic field.

[0032] The beam park device 24 includes a pair of magnetic poles 25c and 25d facing each other in the x direction across the ion beam IB. Each magnetic pole 25c and 25d has a core made of a magnetic material such as iron, with coils 25e and 25f wound around the core. The magnetic poles 25c and 25d and the coils 25e and 25f form an electromagnet that changes the magnetic field in the x direction by changing the current applied to the coils 25e and 25f. The x-direction magnetic field between the magnetic poles 25c and 25d applies a Lorentz force in the -y direction to the ion beam IB traveling in the z direction, so that the ion beam IB can be switched between the irradiation direction D1 and the non-irradiation direction D2, as in FIG. 3 . Note that instead of or in addition to the coils 25e and 25f wound around the magnetic poles 25c and 25d, a coil may be wound around a yoke (not shown) that magnetically connects the pair of magnetic poles 25c and 25d.

[0033] 4, when no magnetic field in the x direction is applied between the pair of magnetic poles 25c and 25d, the beam of the desired ion species used in the ion implantation process is not deflected but travels straight in the irradiation direction and passes through the opening 23a of the mass analysis slit 23, thereby achieving an irradiation-enabled state. On the other hand, when a magnetic field in the x direction is applied between the pair of magnetic poles 25c and 25d, the beam of the desired ion species used in the ion implantation process is deflected in the -y direction, travels in the non-irradiation direction, collides with the beam dump 26 outside the opening 23a of the mass analysis slit 23, and is shielded, thereby achieving an irradiation-disabled state.

[0034] In the above example, when the ion beam is not deflected because no magnetic field is applied between the pair of magnetic poles 25c, 25d, the ion beam travels in the irradiation direction, and when the ion beam is deflected because a magnetic field is applied between the pair of magnetic poles 25c, 25d, the ion beam travels in the non-irradiation direction, but it is also possible for the ion beam to travel in the non-irradiation direction when not deflected and the ion beam to travel in the irradiation direction when deflected. Also, the ion beam traveling in the irradiation direction and the ion beam traveling in the non-irradiation direction may be deflected by different magnetic fields applied between the pair of magnetic poles 25c, 25d.

[0035] 1 to 3 and the modified example of FIG. 4, the mass analysis magnet 21 in the mass analysis unit 20 may be used as a beam deflection device that deflects the ion beam between an irradiation-enabled direction and an irradiation-disabled direction using a magnetic field. As described above, the mass analysis magnet 21 applies a magnetic field in the -y direction to deflect the ion beam in the x direction, and in the irradiation-enabled state, ion species having a desired mass-to-charge ratio M pass through the opening 23a of the mass analysis slit 23. On the other hand, in the irradiation-disabled state, the magnetic field in the y direction of the mass analysis magnet 21 is changed to deflect the ion beam containing the desired ion species to a position in the x direction that is offset from the opening 23a of the mass analysis slit 23. In this case, the beam dump 26, which is located at a position offset from the opening 23a in the y direction in the example of FIG. 2, is located at a position offset from the opening 23a in the x direction. In addition, an electric field deflection type beam park device 24 as in the embodiment of Figures 1 to 3 and a magnetic field deflection type beam park device 24 as in the modified example of Figure 4 may be used together to deflect the ion beam between a direction in which irradiation is possible and a direction in which irradiation is not possible.

[0036] Hereinafter, the various beam park devices 24 described above and the mass analysis magnet 21 in the mass analysis section 20 that functions as a beam deflection device will be collectively referred to as the beam deflection device 24.

[0037] 1 and 2, an injector Faraday cup 28, which also functions as a beam blocking mechanism, is provided downstream of the mass analysis slit 23. The injector Faraday cup 28 can be moved into and out of the beamline A by the operation of an injector driver 29. The injector driver 29 moves the injector Faraday cup 28 in a direction (e.g., the y direction) perpendicular to the direction in which the beamline A extends (the z direction). As shown by the dashed line in FIG. 2, when the injector Faraday cup 28 is positioned on the beamline A, it is in a blocking state in which the ion beam traveling downstream is physically blocked. On the other hand, as shown by the solid line in FIG. 2, when the injector Faraday cup 28 is removed from the beamline A, it is in an unblocking state in which the ion beam traveling downstream passes without being physically blocked. In this way, the injector Faraday cup 28 and the injector driver 29 function as a beam blocking mechanism that can be switched between a blocking state in which the ion beam is physically blocked and an unblocking state in which the ion beam passes.

[0038] The injector Faraday cup 28 measures the beam current of the ion beam mass-analyzed by the mass analyzer 20. By measuring the beam current while changing the magnetic field strength of the mass analyzer magnet 21, the injector Faraday cup 28 can obtain the mass analysis spectrum of the ion beam. This mass analysis spectrum is used, for example, to calculate the mass resolution of the mass analyzer 20.

[0039] 5 to 9 show modified examples of the beam blocking mechanism. A in each figure (e.g., FIG. 5A) shows a blocking state in which the beam blocking mechanism physically blocks the ion beam IB, and B in each figure (e.g., FIG. 5B) shows a non-blocking state in which the beam blocking mechanism allows the ion beam IB to pass.

[0040] The beam blocking mechanism in Fig. 5 is a shielding plate 28a in the shape of a plate, such as a circle. In the blocking state in Fig. 5A, the shielding plate 28a is disposed on the beam line A and physically blocks the ion beam IB. In the non-blocking state in Fig. 5B, the shielding plate 28a is rotated from the blocking state around a rotation axis in a direction (e.g., x direction) perpendicular to the direction in which the beam line A extends (z direction) as shown by the arrow in the figure, and is therefore removed from the beam line A, allowing the ion beam IB to pass through.

[0041] The beam blocking mechanism in Fig. 6 is a shielding plate 28b in the shape of a plate, such as a circle. In the blocking state in Fig. 6A, the shielding plate 28b is disposed on the beamline A and physically blocks the ion beam IB. In the non-blocking state in Fig. 6B, the shielding plate 28b is moved from the blocking state in a direction (e.g., the y direction) perpendicular to the direction in which the beamline A extends (the z direction) as shown by the arrow in the figure, and is therefore removed from the beamline A, allowing the ion beam IB to pass through.

[0042] The beam blocking mechanism in Fig. 7 is a disk-shaped shielding plate 28c, and a window 28d or hole through which the ion beam IB can pass is formed in at least one location on the outer periphery thereof. In the blocked state of Fig. 7A, the window 28d is off the beamline A, so the portions of the shielding plate 28c other than the window 28d physically block the ion beam IB. In the non-blocking state of Fig. 7B, the window 28d of the shielding plate 28c, which has been rotated from the blocked state around a rotation axis parallel to the direction in which the beamline A extends (the z direction) as shown by the arrow in the figure, is positioned on the beamline A, so that the ion beam IB can pass through the window 28d.

[0043] The beam blocking mechanism in Fig. 8 is a plate-shaped shielding plate 28e that can rotate around a rotation axis 28f in a direction (e.g., x direction) perpendicular to the direction in which the beamline A extends (z direction). In the blocking state in Fig. 8A, the shielding plate 28e is disposed on the beamline A and physically blocks the ion beam IB. In the non-blocking state in Fig. 8B, the shielding plate 28e is rotated around the rotation axis 28f from the blocking state as shown by the arrow in the figure and moves out of the beamline A, allowing the ion beam IB to pass through.

[0044] The beam blocking mechanism in Fig. 9 is a block-shaped shield 28g in which a passage 28h through which the ion beam IB can pass is formed, and which is rotatable around a rotation axis in a direction (e.g., x direction) perpendicular to the direction in which the beamline A extends (z direction). In the blocked state in Fig. 9A, the passage 28h intersects or is perpendicular to the beamline A, so that the portion of the shield 28g other than the passage 28h physically blocks the ion beam IB. In the unblocked state in Fig. 9B, the passage 28h of the shield 28g, which has been rotated from the blocked state as shown by the arrow in the figure, is positioned substantially parallel to the beamline A, so that the ion beam IB can pass through the passage 28h.

[0045] Hereinafter, the beam blocking mechanism in FIGS. 5 to 9 and the injector Faraday cup 28 in FIGS. 1 and 2 will be collectively referred to as the beam blocking mechanism 28.

[0046] 1 and 2, the beam shaping unit 30 includes a converging / diverging device such as a converging / diverging quadrupole lens (Q lens) and shapes the ion beam that has passed through the mass analysis unit 20 into a desired cross-sectional shape. For example, the beam shaping unit 30, which is configured with an electric field type triple-stage quadrupole lens (also called a triplet Q lens), has three quadrupole lenses 30a, 30b, and 30c. By using the three lens devices 30a to 30c, the beam shaping unit 30 can independently adjust the convergence or divergence of the ion beam in the x and y directions. The beam shaping unit 30 may include a magnetic field type lens device, or may include a lens device that uses both an electric field and a magnetic field to shape the ion beam.

[0047] The beam scanning device 32 reciprocates and scans a predetermined scanning angle range in the x direction with the ion beam (shaped by the beam shaping unit 30) that is irradiated onto the wafer W by at least one of an electric field and a magnetic field. As will be described later, the beam scanning device 32 can also be used as a beam deflection device that deflects the ion beam between an irradiation direction and an unirradiation direction, instead of or in addition to the beam park device 24. The beam scanning device 32 includes a pair of scanning electrodes facing each other in the beam scanning direction (x direction). The pair of scanning electrodes is connected to a variable voltage power supply (not shown). By periodically changing the voltage applied between the pair of scanning electrodes, the electric field between the electrodes is changed, thereby deflecting the ion beam to various angles within the zx plane. As a result, the ion beam is scanned over the entire scanning range in the x direction. In FIG. 1, the arrow X indicates the scanning direction and scanning range of the ion beam, and the dashed lines indicate multiple trajectories of the ion beam within the scanning range.

[0048] The beam collimator 34 adjusts the traveling direction of the ion beam scanned by the beam scanning device 32 to be approximately parallel to the designed trajectory of the beamline A. The beam collimator 34 includes a plurality of arc-shaped collimator lens electrodes each having a slit for passing the ion beam at the center in the y direction. The collimator lens electrodes are connected to a high-voltage power supply (not shown), and an electric field generated by an applied voltage acts on the ion beam to adjust the traveling direction of the ion beam to be approximately parallel to the beamline A. The beam collimator 34 may be replaced with another type of beam collimator, for example, a magnet device that uses a magnetic field. An AD (Accel / Decel) column (not shown) for accelerating or decelerating the ion beam may be provided downstream of the beam collimator 34.

[0049] The angular energy filter (AEF) 36 analyzes the energy of the ion beam and deflects ions of the required energy downward (in the -y direction) to guide them to the implantation processing chamber 16. The angular energy filter 36 includes a pair of AEF electrodes for electric field deflection connected to a high-voltage power supply (not shown). In FIG. 2, a positive voltage is applied to the upper (+y side) AEF electrode and a negative voltage is applied to the lower (-y side) AEF electrode, thereby deflecting a positively charged ion beam downward (in the case of a negatively charged ion beam, a negative voltage is applied to the upper AEF electrode and a positive voltage is applied to the lower AEF electrode). The angular energy filter 36 may be configured with a magnet device for magnetic field deflection, or may be configured with a combination of an AEF electrode pair for electric field deflection and a magnet device for magnetic field deflection.

[0050] As described above, the beamline device 14 supplies the ion beam to be irradiated onto the wafer W as the workpiece to the implantation processing chamber 16. The implantation processing chamber 16 includes, in order from the upstream side of the beamline A, an energy slit 38, a plasma shower device 40, side cups 42 (42R, 42L), a profiler cup 44, and a beam stopper 46. As shown in FIG. 2, the implantation processing chamber 16 includes a platen driving device 50 that holds one or more wafers W.

[0051] The energy slit 38 is provided downstream of the angular energy filter 36 and, together with the angular energy filter 36, analyzes the energy of the ion beam incident on the wafer W. The energy slit 38 is an energy defining slit (EDS) that is a horizontally long slit in the beam scanning direction (x direction). The energy slit 38 passes ion beams whose energy is a desired value or within a desired range toward the wafer W and blocks other ion beams.

[0052] The plasma shower device 40 is disposed downstream of the energy slit 38. The plasma shower device 40 supplies low-energy electrons to the ion beam and / or the surface of the wafer W (wafer processing surface) according to the beam current of the ion beam, thereby suppressing the accumulation of positive charges (so-called charge-up) on the wafer processing surface caused by ion implantation. The plasma shower device 40 includes, for example, a shower tube through which the ion beam passes and a plasma generator that supplies electrons into the shower tube.

[0053] The side cups 42 (42R, 42L) measure the beam current of the ion beam during ion implantation processing of the wafer W. As shown in FIG. 1 , the side cups 42R, 42L are positioned offset to the left or right (x direction) from the wafer W placed on the beam line A, and are positioned so as not to block the ion beam directed toward the wafer W during ion implantation. Because the ion beam is scanned in the x direction beyond the range where the wafer W is located, a portion of the scanned beam is incident on the side cups 42R, 42L even during ion implantation. In this way, the beam current amount during ion implantation processing is measured by the side cups 42R, 42L. Because the ion beam incident on the side cups 42R, 42L during ion implantation is not irradiated onto the wafer W as the workpiece, the side cups 42R, 42L constitute a second beam current measuring device (the first beam current measuring device will be described later) that measures the beam current of the ion beam directed in a direction that cannot irradiate the wafer W. A beam current measuring device such as a Faraday cup may be provided on the beam dump 26 where the ion beam heading in the non-irradiation direction collides, and used as a second beam current measuring device.

[0054] The profiler cup 44 measures the beam current on the wafer surface to be processed. The profiler cup 44 can be moved in the x direction by the operation of the drive unit 45. During ion implantation, the profiler cup 44 is retracted from the implantation region where the wafer W is located and inserted into the implantation region when the wafer W is not in the implantation region. The profiler cup 44, which is driven in the x direction, can measure the beam current over the entire beam scanning range in the x direction. The profiler cup 44 may include multiple Faraday cups arranged in the x direction so that the beam current can be measured simultaneously at multiple positions in the beam scanning direction (x direction). Since the ion beam incident on the profiler cup 44 is incident on the implantation region where the wafer W as the workpiece is located during ion implantation, the profiler cup 44 constitutes a first beam current measuring device that measures the beam current of the ion beam traveling in an irradiation direction that can irradiate the wafer W. Note that a beam current measuring device such as a Faraday cup may be provided on the beam stopper 46, on which the ion beam traveling in the irradiation direction collides, to serve as the first beam current measuring device.

[0055] The profiler cup 44 includes a first profiler cup 44a and a second profiler cup 44b. The first profiler cup 44a is a first Faraday cup for normal measurement used in a preparation step before the implantation step. The second profiler cup 44b is a second Faraday cup for calibration used in a calibration step. A shielding member 43 is provided in front of the second profiler cup 44b to prevent the ion beam from entering the second profiler cup 44b during the implantation step or preparation step. Note that the shielding member 43 does not have to be a dedicated member for blocking the ion beam from entering the second profiler cup 44b, and may be a part or the entirety of any structure provided in the implantation processing chamber 16.

[0056] The second profiler cup 44b may have higher measurement accuracy than the first profiler cup 44a. For example, the second profiler cup 44b may have components machined with higher accuracy than the first profiler cup 44a, thereby reducing the tolerance of the size of the aperture through which the ion beam to be measured is incident. The second profiler cup 44b may also have a slower degradation of measurement accuracy with use than the first profiler cup 44a. For example, the second profiler cup 44b may be made of components that are more resistant to wear than the first profiler cup 44a.

[0057] The first profiler cup 44a and the second profiler cup 44b can be driven independently of each other by a drive unit 45. The first profiler cup 44a can move in the x-direction along a first drive shaft 45a of the drive unit 45. The second profiler cup 44b can move in the x-direction along a second drive shaft 45b of the drive unit 45. The directions of movement of the first profiler cup 44a and the second profiler cup 44b are approximately parallel to each other.

[0058] At least one of the side cup 42 and the profiler cup 44 may include a single Faraday cup for measuring the beam current, or may include an angle measuring device for measuring angular information of the ion beam. The angle measuring device may include, for example, a slit and multiple current detectors spaced apart from the slit in the beam propagation direction (z direction). This angle measuring device can measure the angular component or angular distribution of the beam in the slit width direction by measuring the ion beam that has passed through the slit with multiple current detectors aligned in the slit width direction. At least one of the side cup 42 and the profiler cup 44 may include a first angle measuring device capable of measuring angular information in the x direction and / or a second angle measuring device capable of measuring angular information in the y direction.

[0059] The platen drive device 50 includes a wafer holding device 52 , a reciprocating mechanism 54 , a twist angle adjustment mechanism 56 , and a tilt angle adjustment mechanism 58 .

[0060] The wafer holding device 52 for holding the wafer W to be irradiated with the ion beam constitutes a support mechanism for supporting the wafer W and includes an electrostatic chuck as an electrostatic holding mechanism that holds the supported wafer W by electrostatic attraction. The wafer holding device 52 may also include a temperature adjustment device for heating or cooling the wafer W to be ion implanted. The temperature adjustment device may be a heating device that heats the wafer W to a temperature 20°C or more, 50°C or more, or 100°C or more higher than room temperature, or a cooling device that cools the wafer W to a temperature 20°C or more, 50°C or more, or 100°C or more lower than room temperature. The temperature of the wafer W affects the concentration distribution (implantation profile) of ions implanted into the wafer W and the crystal defects (implantation damage) formed in the wafer W by ion implantation. The process of irradiating a wafer W at a temperature higher than room temperature with an ion beam is also called high-temperature implantation. The process of irradiating a wafer W at a temperature lower than room temperature with an ion beam is also called low-temperature implantation.

[0061] The reciprocating mechanism 54 is a drive mechanism that reciprocates the wafer holding device 52, including the support mechanism, in a direction that intersects with the ion beam. The reciprocating mechanism 54 reciprocates the wafer holding device 52, including the support mechanism, in a reciprocating direction (y direction) that is perpendicular to the beam scanning direction (x direction), thereby causing the wafer W held by the wafer holding device 52 to reciprocate in the y direction. In Figure 2, the arrow Y indicates the direction and range of the reciprocating motion of the wafer W.

[0062] The twist angle adjustment mechanism 56, which constitutes the implantation angle adjustment mechanism, is a mechanism for adjusting the rotation angle of the wafer W, and adjusts the twist angle between an alignment mark provided on the outer periphery of the wafer W and a reference position by rotating the wafer W at the center of the wafer's processing surface around a rotation axis that is normal to the wafer's processing surface at right angles. Here, the alignment mark on the wafer W is, for example, a notch or orientation flat provided on the outer periphery of the wafer W, and serves as a reference for the crystal orientation of the wafer W and the angular position of the wafer W in the circumferential direction. The twist angle adjustment mechanism 56 is provided between the wafer holding device 52 and the reciprocating motion mechanism 54, and is reciprocated together with the wafer holding device 52 by the reciprocating motion mechanism 54.

[0063] The tilt angle adjustment mechanism 58, which constitutes the implantation angle adjustment mechanism, adjusts the tilt of the wafer W by adjusting the tilt angle between the direction of travel of the ion beam toward the wafer surface to be processed and the normal to the wafer surface to be processed. In the example of Figure 2, the tilt angle of the wafer W is the rotation angle around the x-axis as the central axis of rotation, and is adjusted by the tilt angle adjustment mechanism 58. The tilt angle adjustment mechanism 58 is provided between the reciprocating mechanism 54 and the inner wall of the implantation processing chamber 16, and adjusts the tilt angle of the wafer W by rotating the entire platen drive device 50, including the reciprocating mechanism 54, in the R direction (Figure 2).

[0064] The platen drive device 50 holds the wafer W so that the wafer W can be moved between an ion implantation position where the wafer W is irradiated with an ion beam and a transfer position where the wafer W is loaded or unloaded relative to the wafer transport device 18. That is, the platen drive device 50 constitutes a moving device that moves the wafer holding device 52 between the ion implantation position where the wafer W supported by the wafer holding device 52 is irradiated with an ion beam and a transfer position where the wafer transport device 18 can transfer the wafer W relative to the wafer holding device 52. FIG. 2 shows a state in which the wafer W and the wafer holding device 52 are at the ion implantation position, and the wafer holding device 52 holds the wafer W so as to intersect with the beamline A. The transfer position of the wafer W corresponds to the position of the wafer holding device 52 when a transfer mechanism or transfer robot provided in the wafer transport device 18 loads or unloads the wafer W through the transfer port 48.

[0065] The beam stopper 46 is provided at the most downstream position of the beam line A, and is attached to, for example, the inner wall of the implantation processing chamber 16. When the wafer W and the profiler cup 44 are not present on the beam line A, the ion beam is incident on the beam stopper 46. The beam stopper 46 is disposed near a transfer port 48 that connects the implantation processing chamber 16 and the wafer transfer device 18, and is provided at a position vertically below (in the -y direction) the transfer port 48 in the example of FIG. 2 .

[0066] The beam stopper 46 is provided with a plurality of tuning cups 47 (47a, 47b, 47c, 47d). Each tuning cup 47 is a Faraday cup that measures the beam current of a portion of the ion beam incident on the beam stopper 46. The plurality of tuning cups 47 are arranged at intervals along the x direction. Each tuning cup 47 is used, for example, to simply measure the beam current at the ion implantation position without using the profiler cup 44. These tuning cups 47 and / or the side cup 42 described above constitute a beam current measuring device for dose control that, when a portion of the ion beam is irradiated onto the wafer W, measures the other portion of the ion beam that is not irradiated onto the wafer W as the beam current.

[0067] The ion implantation apparatus 10 further includes a control device 60 that controls the overall operation of the apparatus. The control device 60 is realized by the cooperation of hardware resources such as a computer's central processing unit, memory, input devices, output devices, and peripheral devices connected to the computer, and software executed using these resources. Regardless of the type of computer or its installation location, each function of the control device 60 may be realized by the hardware resources of a single computer or by a combination of hardware resources distributed across multiple computers. Details of the control device 60 will be described later.

[0068] 10 is a front view (from the -z direction) of the processing surface WS of the wafer W to be irradiated with the ion beam B, showing a schematic configuration inside the implantation processing chamber 16. The ion beam B is scanned back and forth in the x direction by the beam scanning device 32 as indicated by the arrow X, forming a scan beam SB that sequentially irradiates an irradiation range 66 extending in the x direction. Here, an ion implantation position 70 where the scan beam SB is incident on the processing surface WS of the wafer W and ions are implanted during the implantation process is shown by a thin solid line.

[0069] The ion beam B is scanned back and forth across an implantation range 62 where the wafer W is located and an irradiation range 66 including monitor ranges 64R and 64L outside the implantation range 62. The left and right side cups 42R and 42L described above are disposed in the left and right monitor ranges 64R and 64L. The left and right side cups 42R and 42L can measure the ion beam B that overscans into the monitor ranges 64R and 64L during the implantation process. The x-direction range of the ion implantation position 70 coincides with the implantation range 62. The y-direction range of the ion implantation position 70 coincides with the y-direction irradiation range of the ion beam B or the scan beam SB. The z-direction position of the ion implantation position 70 coincides with the z-direction position of the processing surface WS of the wafer W.

[0070] During the pouring process, the profiler cups 44 are retracted to a non-irradiated area 68 (68R, 68L) outside the irradiated area 66. In the illustrated example in which the drive unit 45 is located on the right side, the first profiler cup 44a and the second profiler cup 44b are retracted to the non-irradiated area 68R on the right side during the pouring process. Note that when the drive unit 45 is located on the left side, the first profiler cup 44a and the second profiler cup 44b may be retracted to the non-irradiated area 68L on the left side during the pouring process.

[0071] The aforementioned shielding member 43 is also provided in the non-irradiation range 68R on the right side, and is arranged so as to overlap with the second profiler cup 44b in the beam propagation direction (z direction). In other words, the range of the shielding member 43 in the directions (x direction and y direction) perpendicular to the beam propagation direction at least partially overlaps with the range of the second profiler cup 44b in the directions perpendicular to the beam propagation direction. The shielding member 43 blocks the ion beam B heading toward the second profiler cup 44b except during the calibration process. Because the shielding member 43 prevents the ion beam B from entering the second profiler cup 44b except during the calibration process, wear and contamination of the second profiler cup 44b due to the ion beam B can be prevented.

[0072] The wafers W (W1, W1', W2, W2') are driven to reciprocate in the y direction by the reciprocating mechanism 54 of the platen drive device 50 as indicated by the arrow Y, and move sequentially within a reciprocating movement range 69 extending in the y direction. Here, the reciprocating movement range 69 is, for example, a range in the y direction through which the centers (O1, O1', O2, O2') of the processing surfaces WS of the wafers W pass. The position of the upper end of the reciprocating movement range 69 in the y direction corresponds to the position in the y direction of the center O1 of the wafer W1 that has moved to the upper inversion end, and the position of the lower end of the reciprocating movement range 69 in the y direction corresponds to the position in the y direction of the center O2 of the wafer W2 that has moved to the lower inversion end.

[0073] The reciprocating movement range 69 includes a beam irradiation range 65 in which the ion beam B is irradiated onto at least a portion of the processing surface WS of the wafer W, and beam non-irradiation ranges 67 (67U, 67D) adjacent to at least one end of the beam irradiation range 65 and in which the processing surface WS of the wafer W is not irradiated with the ion beam B. In the example of Fig. 10, the beam non-irradiation range 67 includes a first beam non-irradiation range 67U adjacent to the upper end of the beam irradiation range 65 and a second beam non-irradiation range 67D adjacent to the lower end of the beam irradiation range 65.

[0074] Here, the upper end of the first beam non-irradiation range 67U coincides with the upper inverted end of the reciprocating movement range 69, and the lower end of the first beam non-irradiation range 67U (the upper end of the beam irradiation range 65) corresponds to the position in the y direction of the center O1' of the processing surface WS when, for example, the lower end of the wafer W1' has left the ion implantation position 70 in an upward direction. Furthermore, the lower end of the second beam non-irradiation range 67D coincides with the lower inverted end of the reciprocating movement range 69, and the upper end of the second beam non-irradiation range 67D (the lower end of the beam irradiation range 65) corresponds to the position in the y direction of the center O2' of the processing surface WS when, for example, the lower end of the wafer W2' has left the ion implantation position 70 in a downward direction.

[0075] Next, the implantation process, preparation process, and calibration process of the ion implantation apparatus 10, which are executed under the control of the control device 60, will be described.

[0076] 11 is a top view schematically illustrating the interior of the implantation processing chamber 16 during the implantation process. During the implantation process, the wafer W is positioned in the implantation range 62, and the profiler cup 44 is positioned in the non-irradiation range 68. The first profiler cup 44a is positioned at a first retraction position 71 indicated by a dashed line, and the second profiler cup 44b is positioned at a second retraction position 72 indicated by a dashed line. The first retraction position 71 and the second retraction position 72 are adjacent to each other in the x-direction within the non-irradiation range 68R on the right side. The first retraction position 71 is positioned on the left side, closer to the ion implantation position 70 than the second retraction position 72. The shielding member 43 is positioned to block the entrance of the second profiler cup 44b at the second retraction position 72.

[0077] During the implantation process, the side cups 42R and 42L can continuously measure the beam current. Meanwhile, the profiler cup 44 and tuning cup 47 can only intermittently measure the beam current. Therefore, during the implantation process, the dose of ions implanted into the processing surface WS of the wafer W is controlled based on the beam current measured by the side cups 42R and 42L. If the beam current measured by the side cups 42R and 42L changes during the implantation process, the reciprocating mechanism 54 adjusts the speed of the reciprocating motion of the wafer W in the y direction to adjust the dose distribution on the processing surface WS of the wafer W. For example, to achieve a uniform dose distribution within the processing surface WS, the wafer W is reciprocated at a speed proportional to the beam current value monitored by the side cups 42R and 42L. Specifically, if the monitored beam current value increases, the reciprocating motion of the wafer W is increased; if the monitored beam current value decreases, the reciprocating motion of the wafer W is decreased. This prevents variations in the dose within the processing surface WS due to fluctuations in the beam current of the scan beam SB. If the beam current value measured by the side cups 42R, 42L deviates from a predetermined current value by, for example, ±10% or more, the ion implantation apparatus 10 may be stopped as an abnormal value.

[0078] During the implantation process, the control device 60 acquires the beam current values ​​measured by the side cups 42R, 42L and, based on the acquired beam current values, controls the operation of the platen driving device 50. For example, the control device 60 generates a speed command for the platen driving device 50 so that the wafer W is reciprocated in the y direction at a speed proportional to the beam current values ​​acquired from the side cups 42R, 42L.

[0079] 12 is a top view schematically showing the inside of the implantation processing chamber 16 during the preparation step. In the preparation step performed before the implantation step, the beam current of the scan beam SB is measured over the implantation range 62 and the monitor ranges 64R, 64L (i.e., the entire irradiation range 66). The beam current in the implantation range 62 is measured by the first profiler cup 44a and / or the tuning cup 47. The beam current in the monitor ranges 64R, 64L is measured by the side cups 42R, 42L, as in the implantation step.

[0080] In the preparation step, the first profiler cup 44a moves in the x-direction from the first retraction position 71 to one or more first measurement positions 76. Each first measurement position 76 overlaps with the ion implantation position 70 (or implantation range 62) in the beam traveling direction (z-direction) and is located on a plane (hereinafter also referred to as a measurement plane MS) that coincides with the surface WS to be processed in the implantation step. Therefore, the first profiler cup 44a can measure the beam current at the first measurement position 76 included in the ion implantation position 70 where ions are implanted into the wafer W in the implantation step. The first profiler cup 44a may measure the beam current while moving between the multiple first measurement positions 76 along the x-direction, thereby acquiring the beam current distribution in the x-direction at the ion implantation position 70 (or measurement plane MS).

[0081] The multiple tuning cups 47 overlap with the ion implantation position 70 (or implantation range 62) in the beam traveling direction (z direction) like the first measurement position 76, but are spaced downstream (+z direction) from the ion implantation position 70 (or measurement surface MS). Unlike the first profiler cup 44a, the multiple tuning cups 47 do not need to be moved between the retracted position and the measurement position, and therefore can measure the beam current in the implantation range 62 more simply than the first profiler cup 44a.

[0082] In the preparation process, the control device 60 acquires beam current values ​​measured by various Faraday cups in the implantation process chamber 16, specifically, the side cups 42R and 42L, the first profiler cup 44a, and the multiple tuning cups 47. The control device 60 stores the ratios between the beam current values ​​acquired from each Faraday cup and calculates the desired beam current value in the implantation range 62 (the ion implantation position 70 or the surface to be processed WS) based on the beam current values ​​in the monitor ranges 64R and 64L measured by the side cups 42R and 42L during the implantation process. Typically, the ratios between the beam current values ​​measured by each Faraday cup depend on the configuration and settings of the optical system of the beamline device 14 and are approximately constant even if the beam current of the ion beam B extracted from the ion generator 12 fluctuates slightly. In other words, once the configuration and settings of the optical system of the beamline device 14 are determined in the preparation process, the ratios between the beam current values ​​remain almost constant even during the subsequent implantation process. Therefore, based on the ratio between the beam current values ​​stored in the preparation process and the beam current values ​​measured by the side cups 42R and 42L in the implantation process, the beam current value at the ion implantation position 70 (implantation range 62 or processed surface WS) where ions are implanted into the wafer W in the implantation process can be calculated.

[0083] 11 and the preparation step of FIG. 12, the second profiler cup 44b is not used. Throughout the preparation step and the implantation step, the second profiler cup 44b remains at the second retraction position 72 where the scan beam SB is blocked by the shielding member 43. The second profiler cup 44b is used in a calibration step for calibrating the beam current measurement value of the first profiler cup 44a. The calibration step is performed when an unused ion implanter 10 starts operating, during maintenance such as cleaning or replacing the first profiler cup 44a, etc.

[0084] FIG. 13 is a top view schematically illustrating the interior of the implantation processing chamber 16 during the calibration process. During the calibration process, the second profiler cup 44b moves in the x direction from the second retraction position 72 to one or more second measurement positions 77. Like the first measurement positions 76, each second measurement position 77 overlaps with the ion implantation position 70 (or implantation range 62) in the beam propagation direction (z direction) and is located on a plane (measurement plane MS) that coincides with the surface WS to be processed during the implantation process. Each second measurement position 77 at least partially coincides with each first measurement position 76. The second profiler cup 44b can measure the beam current at the same position as the surface WS to be processed during the implantation process and at the same position as the first profiler cup 44a during the preparation process. The second profiler cup 44b may measure the beam current while moving between the multiple second measurement positions 77 along the x direction to obtain the beam current distribution in the x direction at the ion implantation position 70 (or measurement plane MS).

[0085] During the calibration process, the first profiler cup 44a may be positioned at a third retraction position 73, which is different from the first retraction position 71. In the illustrated example, the third retraction position 73 is located within the non-irradiation range 68L on the left side. In this case, the third retraction position 73 is located on the opposite side of the injection range 62 from the first retraction position 71 and the second retraction position 72. By retracting the first profiler cup 44a to the third retraction position 73, the second profiler cup 44b will not interfere with the first profiler cup 44a when moving from the second retraction position 72 to the second measurement position 77.

[0086] In the calibration process, the first profiler cup 44a and the second profiler cup 44b may be driven separately or independently, or may be driven simultaneously. In the former case of independent driving, the first profiler cup 44a is first moved to at least one of the first measurement positions 76 to measure the beam current value at the ion implantation position 70. Subsequently, the second profiler cup 44b is moved to at least one of the second measurement positions 77 to measure the beam current value at the ion implantation position 70. In the case of simultaneous driving, the first profiler cup 44a measures the beam current value at one or more of the first measurement positions 76 while moving in the x direction from the first retraction position 71 toward the third retraction position 73. Simultaneously, the second profiler cup 44b moves from the second retraction position 72 to at least one of the second measurement positions 77 to measure the beam current value. By operating the profiler cup 44 in the above manner, the first profiler cup 44a and the second profiler cup 44b can measure the scan beam SB at the same measurement position at the ion implantation position 70 under the same conditions.

[0087] The control device 60 determines calibration parameters for calibrating the measurement values ​​of the first profiler cup 44a based on the beam current values ​​measured by the first profiler cup 44a and the second profiler cup 44b. If the first beam current measurement value acquired by the first profiler cup 44a in the calibration process is I1 and the second beam current measurement value acquired by the second profiler cup 44b in the calibration process is I2, the calibration parameter k is expressed as the ratio I2 / I1 of the first beam current measurement value I1 to the second beam current measurement value I2 (k=I2 / I1). Using the calibration parameter k, the calibrated beam current value I2 based on the second profiler cup 44b can be calculated as I2=k×I1 based on the beam current measurement value I1 acquired by the first profiler cup 44a in the preparation process. In the implantation process, the ion dose on the processing surface WS of the wafer W is controlled based on the beam current value k×I1 calibrated using the calibration parameter k.

[0088] Next, the implantation angle adjustment mechanism including the twist angle adjustment mechanism 56 and the tilt angle adjustment mechanism 58 will be described. This implantation angle adjustment mechanism adjusts the implantation angle of the wafer W supported by the wafer holding device 52 relative to the ion beam. In this embodiment, multiple ion implantation processes with different implantation conditions (implantation angles) are successively performed on the same wafer W. Below, an example will be described in which the implantation angle adjustment mechanism adjusts the implantation angle to four different angles and four ion implantation processes at each of the implantation angles are successively performed on the same wafer W. Each implantation angle is determined by a combination of a constant tilt angle θ (not equal to 0 degrees) set by the tilt angle adjustment mechanism 58 and four different twist angles φ (e.g., 0 degrees, 90 degrees, 180 degrees, and 270 degrees) set by the twist angle adjustment mechanism 56. Note that, in each ion implantation process with a different implantation angle, the dose distribution within the processing surface WS of the wafer W may be set to have a desired non-uniform shape, or the ion implantation conditions may be set so that the current density distribution of the ion beam irradiated to each region within the processing surface WS varies.

[0089] 14 is a diagram schematically illustrating an implantation process using a non-zero tilt angle θ. Here, a wafer W having a gate 80, a drain region 83, and a source region 84 formed on its processing surface WS is tilted at a tilt angle θ with respect to an ion beam B, and the ion beam B irradiated onto the lower part of the gate 80 forms a halo implantation region 85. The tilt angle θ of the wafer W is set to several degrees or more, preferably ten degrees or more, so that the ion beam B is effectively irradiated onto the lower part of the gate 80. Note that such a "non-zero tilt angle implantation process" may be performed to form any ion implantation region other than a halo implantation region.

[0090] 15(a) to 15(d) schematically show changes in the twist angle φ caused by the twist angle adjustment mechanism 56. The twist angle φ is the rotation angle of the wafer W about a rotation axis that is a normal line (a straight line perpendicular to the plane of FIG. 15) passing through the center of the processing surface of the wafer W. The twist angle φ corresponds to, for example, the rotational position (notch position) of an alignment mark 88 provided on the outer periphery of the wafer W. If the twist angle φ is φ0 when the alignment mark 88 is located at the bottom end of the wafer W in FIG. 15(a), the twist angle φ is φ0+90 degrees when the alignment mark 88 is located at the left end of the wafer W in FIG. 15(b), the twist angle φ is φ0+180 degrees when the alignment mark 88 is located at the top end of the wafer W in FIG. 15(c), and the twist angle φ is φ0+270 degrees when the alignment mark 88 is located at the right end of the wafer W in FIG. 15(d). 15(a) to 15(d), a gate 81 extending in a first direction and a gate 82 extending in a second direction perpendicular to the first direction are formed on the processing surface of the wafer W. The twist angle adjustment mechanism 56 sequentially switches the twist angle of this wafer W to four different angles: φ0, φ0+90 degrees, φ0+180 degrees, and φ0+270 degrees, and four ion implantation processes at each twist angle φ are successively performed on the same wafer W.

[0091] Hereinafter, when the twist angle adjustment mechanism 56 switches the twist angle φ of the wafer W, the twist angle φ before switching will be collectively referred to as the first twist angle φ1, and the twist angle φ after switching will be collectively referred to as the second twist angle φ2. Furthermore, the implantation angle resulting from the first twist angle φ1 (and the predetermined tilt angle θ0) will be collectively referred to as the first implantation angle, and the implantation angle resulting from the second twist angle φ2 (and the predetermined tilt angle θ0) will be collectively referred to as the second implantation angle. It is preferable that the difference between the first twist angle φ1 and the second twist angle φ2 be greater than 0 degrees and less than or equal to 180 degrees. In the example of FIG. 15, when the twist angle φ is switched in the order (a) → (b) → (c) → (d), the difference between the first twist angle φ1 and the second twist angle φ2 is constant at 90 degrees. In this way, when N different twist angles φ (N is a natural number equal to or greater than 2, and N=4 in FIG. 15) are applied to the same wafer W, it is preferable that the difference between the first twist angle φ1 and the second twist angle φ2 be the same for all N times (constant at 90 degrees in FIG. 15). In this case, the difference between the first twist angle φ1 and the second twist angle φ2 is 360 degrees divided by N (360 degrees ÷ 4 = 90 degrees in FIG. 15). Furthermore, it is preferable that the number N of applied twist angles φ be an even number equal to or greater than 2 and equal to or less than 32.

[0092] 16(a) to 16(d) schematically show non-zero tilt angle implantation processes with different twist angles φ as shown in Fig. 15(a) to 15(d). By performing four implantation processes while holding the tilt angle θ of the wafer W at a non-zero θ0 and switching the twist angle φ as shown in Fig. 15(a) to 15(d), halo implantation regions 85a to 85d can be formed directly below both gate 81 and gate 82, which extend in different directions.

[0093] 16(a), the extension direction (first direction) of gate 81 is set to a twist angle φ0 in the x direction, thereby forming a first halo implantation region 85a in one adjacent region of gate 81 (the lower left region of gate 81 in FIG. 16(a)). In FIG. 16(b), the extension direction (second direction) of gate 82 is switched to a twist angle φ0+90 degrees in the x direction, thereby forming a second halo implantation region 85b in one adjacent region of gate 82 (the lower left region of gate 82 in FIG. 16(b)). In FIG. 16(c), the extension direction (first direction) of gate 81 is switched to a twist angle φ0+180 degrees in the x direction, opposite to that in FIG. 16(a), thereby forming a third halo implantation region 85c in the other adjacent region of gate 81 (the lower left region of gate 81 in FIG. 16(c) and the upper right region of gate 81 in FIG. 16(a)). In Figure 16(d), the extension direction (second direction) of gate 82 is switched to a twist angle of φ0+270 degrees, which is the x direction opposite to that in Figure 16(b), thereby forming a fourth halo implantation region 85d in the other adjacent region of gate 82 (the lower left region of gate 82 in Figure 16(d) and the upper right region of gate 82 in Figure 16(b)).

[0094] As described above, by performing the non-zero tilt angle implantation process multiple times while changing the twist angle φ, halo implantation regions can be formed at locations corresponding to the drain and source regions on both sides of the gate extending in different directions.

[0095] 14 to 16, the implantation angle of the wafer W is switched by the combination of the tilt angle θ set by the tilt angle adjustment mechanism 58 and the twist angle φ set by the twist angle adjustment mechanism 56, but the implantation angle of the wafer W may also be switched by other parameters. For example, in Fig. 10, the implantation angle of the wafer W may also be switched by the combination of rotation angles about two intersecting rotation axes (e.g., a rotation axis in the up-down direction (y direction) and a rotation axis in the left-right direction (x direction) in Fig. 10) within the processing surface WS of the wafer W (within the plane of the paper in Fig. 10).

[0096] 17 is a functional block diagram of the ion implanter 10. The control device 60 of the ion implanter 10 includes a processor 61 and a memory 63. The processor 61 controls each part of the ion implanter 10, such as the beam deflection device 24 (beam park device 24, etc.), the beam blocking mechanism 28 (injector Faraday cup 28, etc.), the beam scanning device 32, the beam current measuring devices 42, 44, 47 (side cup 42, profiler cup 44, tuning cup 47, etc.), and the platen driving device 50 (including the implantation angle adjustment mechanism composed of the twist angle adjustment mechanism 56 and tilt angle adjustment mechanism 58, and the reciprocating mechanism 54). The memory 63 stores a program executed by the processor 61. The processor 61 controls each part of the ion implanter 10 based on the program stored in the memory 63, and executes the following series of steps.

[0097] 18 is a timing chart schematically showing the basic operations in the implantation process of the ion implantation apparatus 10, which are executed by the processor 61 based on the program stored in the memory 63. Each row in Fig. 18 schematically shows the velocity in the y direction of the wafer W as the workpiece of the ion implantation apparatus 10, the implantation angle of the wafer W by the implantation angle adjustment mechanism, and the operating states of the beam deflection device 24 and the beam blocking mechanism 28.

[0098] 18 chronologically shows a series of steps constituting the basic operation of the ion implantation apparatus 10. Each step corresponds to a position or range of the wafer W in the y direction in Fig. 10. Specifically, from left to right in Fig. 18 , in the "beam irradiation range" in the first column, the wafer W moves within the beam irradiation range 65 toward one of the beam non-irradiation ranges 67, in the "beam non-irradiation range" in the second column, the wafer W moves within one of the beam non-irradiation ranges 67 toward the inverted end of the reciprocating movement range 69, in the "inverted end" in the third column, the wafer W stops at the inverted end of the reciprocating movement range 69, in the "beam non-irradiation range" in the fourth column, the wafer W moves within one of the beam non-irradiation ranges 67 toward the beam irradiation range 65, and in the "beam irradiation range" in the fifth column, the wafer W moves within the beam irradiation range 65 toward the other beam non-irradiation range 67.

[0099] In step (a) in the "beam irradiation range" in the first column of FIG. 18, the processor 61 moves the wafer W, which has been adjusted to the first implantation angle by the implantation angle adjustment mechanism, from the beam irradiation range 65 toward one of the beam non-irradiation ranges 67 (67U or 67D) by the reciprocating mechanism 54. The first implantation angle corresponds to the state in FIG. 16(a), for example, and the ion beam B is irradiated onto the wafer W moving within the beam irradiation range 65 at a twist angle φ0 and a tilt angle θ0. The velocity v of the wafer W in the y direction in this "beam irradiation range" y may be constant or may be at a rate controlled according to the beam current measured by the beam current measuring devices 42, 44, 47 to achieve a uniform dose distribution as described with respect to the implantation process of FIG. y The magnitude of v is proportional to the beam current measured by the side cups 42R and 42L during the implantation process. y The magnitude of may be controlled according to the measured beam current value and the position of the wafer W in the y direction in order to achieve a desired dose non-uniformity within the wafer processing surface.

[0100] 18 , in step (b) in the “beam non-irradiation range” column, the processor 61, following step (a), causes the implantation angle adjustment mechanism to start changing the implantation angle of the wafer W from the first implantation angle to the second implantation angle while the wafer W is moving within the beam non-irradiation range 67 after the reciprocating mechanism 54 has moved the wafer W at the first implantation angle from the beam irradiation range 65 to one of the beam non-irradiation ranges 67. Step (b) may be executed a predetermined time after the wafer W enters one of the beam non-irradiation ranges 67 as shown in the figure, or may be executed immediately after the wafer W enters one of the beam non-irradiation ranges 67. Note that step (b) for switching the implantation angle of the wafer W may be executed every time the wafer W enters the beam non-irradiation range 67, or may be executed in the beam non-irradiation range 67 that the wafer W enters after moving within the beam irradiation range 65 a predetermined number of times.

[0101] 11 may detect that the wafer W has entered the beam non-irradiation range 67. While the wafer W is within the beam irradiation range 65, at least one of the tuning cups 47 is shielded by the wafer W, but after the wafer W moves into the beam non-irradiation range 67, the scan beam SB is incident on all of the tuning cups 47. Therefore, by monitoring the measured value of the beam current of each tuning cup 47, it is possible to detect that the wafer W has entered the beam non-irradiation range 67.

[0102] Also, step (b) is preferably performed before the wafer W reaches the inverted end of the reciprocating movement range 69 as shown in the figure. In step (b), the wafer W moving within one of the beam non-irradiation ranges 67 is decelerated (v y In the illustrated example, the wafer W is decelerated over the entire time of the "non-beam irradiation range," but the wafer W may be decelerated over a portion of the time of the "non-beam irradiation range."

[0103] In step (c-1) at the "reversal end" in the third column of FIG. 18, the processor 61, following step (b), reverses the moving direction of the wafer W at the reversal end of one of the beam non-irradiation ranges 67 by using the reciprocating mechanism 54, and moves the wafer W toward the beam irradiation range 65. As shown in the figure, in step (c-1), the wafer W may be stopped at the reversal end of one of the beam non-irradiation ranges 67 for a predetermined stopping time. The "wafer speed" during this time is "0". Meanwhile, the change of the wafer W from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism, which was started in step (b), continues even while the wafer W is stopped at the reversal end. In addition, after the reversal of the moving direction of the wafer W in step (c-1), the wafer W moving within one of the beam non-irradiation ranges 67 is accelerated (0 → -v y In the illustrated example, the wafer W is accelerated over the entire time period of the "non-beam irradiation range", but the wafer W may be accelerated over a portion of the time period of the "non-beam irradiation range".

[0104] 18 , following step (b), while the reciprocating mechanism 54 is moving the wafer W within one of the beam non-irradiation ranges 67 before returning from the beam non-irradiation range 67 to the beam irradiation range 65, the processor 61 completes the change of the wafer W from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism, which was started in step (b). Note that the change of the wafer W from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism may be completed while the wafer W is moving within one of the beam non-irradiation ranges 67 toward the inversion end of the reciprocating movement range 69 in the "beam non-irradiation range" in the second column, or while the wafer W is stopped at the inversion end of the reciprocating movement range 69 at the "inversion end" in the third column.

[0105] In the "beam irradiation range" in the fifth column of FIG. 18, the processor 61 moves the wafer W adjusted to the second implantation angle in step (c-2) within the beam irradiation range 65 toward the other beam non-irradiation range 67 (67D or 67U) by the reciprocating mechanism 54. The second implantation angle corresponds to the state in FIG. 16(b), for example, and the ion beam B is irradiated onto the wafer W moving within the beam irradiation range 65 at a twist angle of φ0+90 degrees and a tilt angle of θ0. The velocity -v of the wafer W in the y direction in this "beam irradiation range" y (The "-" indicates a speed in the opposite direction to the "beam irradiation range" in the first column) may be constant, or may be a speed controlled according to the beam current measured by the beam current measuring devices 42, 44, and 47 to achieve a uniform dose distribution as described with respect to the implantation process of FIG. 11. For example, -v y The magnitude of is proportional to the beam current measured by the side cups 42R and 42L during the implantation process. y The magnitude of may be controlled according to the measured beam current value and the position of the wafer W in the y direction in order to achieve a desired dose non-uniformity within the wafer processing surface.

[0106] According to this embodiment, the change to the second implantation angle begins before the wafer W at the first implantation angle moves from the beam irradiation range 65 to the non-beam irradiation range 67 and arrives at the inversion end of the non-beam irradiation range 67 (step (b)), and the change to the second implantation angle is completed while the wafer W is moving or stopped within the non-beam irradiation range 67 before returning from the non-beam irradiation range 67 to the beam irradiation range 65 (step (c-2)). In this way, by concurrently moving the wafer W within the non-beam irradiation range 67, reversing the movement direction, and changing the implantation angle, the residence time of the wafer W in the non-beam irradiation range 67 can be shortened. As a result, the residence time of the wafer W in the beam irradiation range 65 where the scan beam SB is irradiated becomes relatively long, thereby improving the efficiency of the ion implantation process.

[0107] To complete the change from the first implantation angle to the second implantation angle while the wafer W is in the non-beam irradiation range 67, the sum of the time T1 during which the wafer W moves within the non-beam irradiation range 67 toward the inversion end of the non-beam irradiation range 67, the stop time T2 at the inversion end, and the time T3 during which the wafer W moves within the non-beam irradiation range 67 toward the beam irradiation range 65 is preferably equal to or longer than the time required for the implantation angle adjustment mechanism to change the wafer W from the first implantation angle to the second implantation angle, and specifically, T1+T2+T3 is preferably equal to or longer than 0.05 seconds and equal to or shorter than 1 second, equal to or longer than 0.2 seconds and equal to or shorter than 0.8 seconds, equal to or longer than 0.3 seconds and equal to or shorter than 0.6 seconds, etc. In particular, the stop time T2 at the inversion end is preferably equal to or longer than 0 seconds and equal to or shorter than 0.45 seconds.

[0108] If the change of the wafer W from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism can be completed without stopping the wafer W at the inversion end, the residence time T1+T2+T3 of the wafer W in the non-beam irradiation range 67 can be minimized (T2=0). On the other hand, if the time T1+T3 for the wafer W to travel back and forth in the non-beam irradiation range 67 alone is not enough to complete the change of the wafer W from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism, the wafer W can be stopped at the inversion end for the additional time T2 required to change the implantation angle. In other words, the stop time T2 of the wafer W at the inversion end can be flexibly set from the perspective of completing the change of the implantation angle.

[0109] The "beam deflection device" on the third line and the "beam blocking mechanism" on the fourth line in Figure 18 are controlled by the processor 61 to reliably retract the ion beam B so that the scan beam SB does not erroneously irradiate the wafer W while changing the implantation angle of the wafer W within the beam non-irradiation range 67. "ON" and "OFF" in the "beam deflection device" indicate the operating state of the beam deflection device 24; when "ON", the beam deflection device 24 deflects the ion beam B in a direction that does not allow irradiation, and when "OFF" the beam deflection device 24 is not operating, the ion beam B moves in a direction that allows irradiation. "ON" and "OFF" in the "beam blocking mechanism" indicate the operating state of the beam blocking mechanism 28; when "ON", the beam blocking mechanism 28 is in a blocking state that physically blocks the ion beam B, and when "OFF", the beam blocking mechanism 28 is in a non-blocking state that allows the ion beam B to pass.

[0110] In step (d), the processor 61 switches the beam deflection device 24 to the non-irradiation state "ON" while the wafer W is being moved within the beam non-irradiation range 67 by the reciprocating mechanism 54 in step (b) and before the implantation angle adjustment mechanism starts changing the implantation angle of the wafer W from the first to the second. In step (f), the processor 61 switches the beam blocking mechanism 28 to the blocking state "ON" after step (d). Step (f) is preferably executed before the implantation angle adjustment mechanism starts changing the implantation angle of the wafer W from the first to the second implantation angle in step (b). Since the ion beam B deflected by the beam deflection device 24 proceeds in the non-irradiation direction, and further, the beam blocking mechanism 28 physically blocks the ion beam B in case the beam deflection device 24 does not operate normally, it is possible to reliably prevent the scan beam SB from erroneously irradiating the wafer W while the implantation angle of the wafer W within the beam non-irradiation range 67 is being changed.

[0111] In step (e), the processor 61 switches the beam deflector 24 to the irradiation enable state "OFF" while the wafer W is being moved within the beam non-irradiation range 67 by the reciprocating mechanism 54 in step (c-1) and after the implantation angle adjustment mechanism has completed changing the implantation angle of the wafer W from the first to the second implantation angle in step (c-2). In step (g), the processor 61 switches the beam blocking mechanism 28 to the non-blocking state "OFF" before step (e). Step (g) is preferably executed after the implantation angle adjustment mechanism has completed changing the implantation angle of the wafer W from the first to the second implantation angle in step (c-2).

[0112] Next, a modification of the basic operation in the implantation process of the ion implantation apparatus 10 will be described.

[0113] In the first modification, in addition to the beam blocking mechanism 28, a first beam current measuring device 46 and / or a second beam current measuring device 42 are used. When the first beam current measuring device 46 (e.g., beam stopper 46 configured as a beam current measuring device) that measures the beam current of the ion beam heading in the irradiation possible direction does not measure a beam current equal to or greater than a first predetermined value, the processor 61 may determine that the irradiation is impossible and switch the beam blocking mechanism 28 to the blocking state. That is, when the beam current measured by the first beam current measuring device 46 is less than the first predetermined value, the intensity of the ion beam used in the ion implantation process in the implantation process chamber 16 may be insufficient, and the beam blocking mechanism 28 is switched to the blocking state and the ion implantation process is interrupted or stopped. Note that, in addition to or instead of the first beam current measuring device 46, when the second beam current measuring device 42 (e.g., side cup 42) or tuning cup 47 does not measure a beam current equal to or greater than the first predetermined value or a predetermined value equivalent thereto, the processor 61 may determine that the irradiation is impossible and switch the beam blocking mechanism 28 to the blocking state.

[0114] When a beam current equal to or greater than a second predetermined value is measured by a second beam current measuring device 42 (such as the side cup 42) that measures the beam current of the ion beam heading in an unirradiable direction, the processor 61 may determine that the state is unirradiable and switch the beam blocking mechanism 28 to the blocking state. That is, when the beam current measured by the second beam current measuring device 42 is equal to or greater than the second predetermined value, there is a risk that the intensity of the ion beam not used for the ion implantation process in the implantation process chamber 16 is excessive, and therefore the processor 61 switches the beam blocking mechanism 28 to the blocking state and interrupts or stops the ion implantation process. Note that the second predetermined value is preferably set so that the beam current density converted therefrom is greater than the beam current density converted from the first predetermined value.

[0115] In a second modified example, the beam scanning device 32 is also used as the beam deflection device 24. For example, instead of or in addition to the beam park device 24 that functions as the beam deflection device 24 in Figures 1 and 2, the function of the beam deflection device 24 is realized by the beam scanning device 32. In this case, the beam deflection device 24 and the beam scanning device 32 are the same device. Figure 19 schematically shows an example in which the beam scanning function of the beam scanning device 32 and the beam deflection function of the beam deflection device 24 are realized by a single beam scanning device 32.

[0116] When realizing its original beam scanning function, the beam scanning device 32 reciprocates and scans a predetermined scan angle range in the x direction (irradiation range 66 in FIG. 10) with the ion beam irradiated onto the wafer W. Here, the scan angle range is an angle range that includes the possible irradiation direction (the direction of the beam line A that can reach the wafer), and θ2 shown in the figure is the maximum scan angle that the outermost angle of the scan angle range makes with the reference trajectory direction (the direction of the beam line A in a non-scanning state where the voltage applied between the scanning electrode pair of the beam scanning device 32 is approximately zero). In other words, the scan angle range of the beam scanning device 32 is a range of ±θ2 with respect to the reference trajectory direction.

[0117] On the other hand, when the beam scanning device 32 functions as the beam deflection device 24, it deflects the ion beam in an unirradiable direction outside the scanning angle range. Here, the deflection angle θ1 of the ion beam is the angle between the unirradiable direction and the reference trajectory direction, and is greater than the maximum scanning angle θ2 (θ1>θ2). Since the wafer W is not positioned on the path of the ion beam deflected at the deflection angle θ1, the deflection angle θ1 becomes an unirradiable direction in which the ion beam cannot irradiate the wafer W. Note that the beam scanning device 32 functioning as the beam deflection device 24 may deflect the ion beam at a deflection angle of −θ1. Furthermore, a beam dump or the like may be provided on the path of the ion beam deflected at the deflection angle θ1 (or −θ1), where the ion beam collides and is shielded.

[0118] 18, in the "beam irradiation range" in the basic operation of the implantation process, the beam scanning device 32 realizes its original beam scanning function, and reciprocates to scan the scan angle range (-θ2 to +θ2) with the ion beam to be irradiated onto the wafer W. In addition, in the "beam non-irradiation range" and "reverse end" in the basic operation of the implantation process in Fig. 18, the beam scanning device 32 functions as the beam deflection device 24, and deflects the ion beam in a non-irradiation direction (θ1 or -θ1) outside the scan angle range.

[0119] The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components and treatment processes, and that such modifications are also within the scope of the present invention.

[0120] The functional configuration of each device described in the embodiments can be realized by hardware resources, software resources, or a combination of hardware and software resources. Examples of hardware resources include processors, ROMs, RAMs, and other LSIs. Examples of software resources include operating systems, applications, and other programs. [Explanation of symbols]

[0121] 10 ion implantation device, 12 ion generation device, 14 beam line device, 16 implantation processing chamber, 23 mass analysis slit, 24 beam deflection device, 28 beam blocking mechanism, 32 beam scanning device, 42 second beam current measuring device, 46 first beam current measuring device, 47 tuning cup, 50 platen drive device, 52 wafer holding device, 54 reciprocating motion mechanism, 56 twist angle adjustment mechanism, 58 tilt angle adjustment mechanism, 60 control device, 61 processor, 63 memory, 65 beam irradiation range, 67 beam non-irradiation range, 69 reciprocating movement range.

Claims

1. a support mechanism for supporting an object to be irradiated with an ion beam; an implantation angle adjustment mechanism capable of adjusting an implantation angle of the workpiece supported by the support mechanism with respect to the ion beam; a drive mechanism that reciprocates the support mechanism in a direction intersecting the ion beam, the reciprocating movement range of which includes a beam irradiation range in which the ion beam is irradiated onto at least a part of the workpiece, and a beam non-irradiation range adjacent to at least one end of the beam irradiation range in which the workpiece is not irradiated with the ion beam; a processor for controlling the implantation angle adjustment mechanism and the drive mechanism; A memory in which a program is stored; Equipped with The processor, based on the program, (a) moving the workpiece, which has been adjusted to a first implantation angle by the implantation angle adjustment mechanism, from the beam irradiation range to the beam non-irradiation range by the drive mechanism; (b) following the step (a), by the driving mechanism, the workpiece at the first implantation angle is moved from the beam irradiation range to the non-beam irradiation range, and then moved within the non-beam irradiation range, and the direction of movement of the workpiece is reversed at an end of the non-beam irradiation range to move the workpiece toward the beam irradiation range; (c) initiating a change of the implantation angle of the object from the first implantation angle to a second implantation angle different from the first implantation angle by the implantation angle adjustment mechanism while the drive mechanism is moving within the beam non-irradiation range in the step (b), and completing the change to the second implantation angle while the step (b) is being performed; An ion implanter that performs

2. 2. The ion implanter according to claim 1, wherein the non-beam irradiated area includes a first non-beam irradiated area adjacent to one end of the beam irradiated area and a second non-beam irradiated area adjacent to the other end of the beam irradiated area.

3. 3. The ion implantation apparatus according to claim 1, wherein said step (b) is performed every time said workpiece enters said beam irradiation range.

4. 3. The ion implantation apparatus according to claim 1, wherein said step (b) is performed in said non-beam irradiation range, which said object enters after moving through said beam irradiation range a predetermined number of times.

5. 5. The ion implantation apparatus according to claim 1, wherein in said step (b), said object is stopped at an end of said non-beam irradiated range for a predetermined stopping time.

6. 6. The ion implantation apparatus according to claim 5, wherein in step (b), the sum of the time during which the workpiece moves within the non-beam irradiation range toward the end of the non-beam irradiation range, the stop time, and the time during which the workpiece moves within the non-beam irradiation range toward the beam irradiation range is equal to or greater than the time required for the implantation angle adjustment mechanism to change the implantation angle of the workpiece from the first implantation angle to the second implantation angle.

7. 7. The ion implantation apparatus of claim 6, wherein in step (b), the sum of the time during which the workpiece moves within the non-beam irradiation range toward the end of the non-beam irradiation range, the stop time, and the time during which the workpiece moves within the non-beam irradiation range toward the beam irradiation range is 0.05 seconds or more and 1 second or less.

8. 8. The ion implanter of claim 7, wherein the dwell time is greater than 0 seconds and less than or equal to 0.45 seconds.

9. 9. The ion implantation apparatus according to claim 5, wherein in step (c), at least one of changing the implantation angle of the object from the first implantation angle to the second implantation angle by the implantation angle adjustment mechanism and completing the change is performed while the drive mechanism is moving within the beam non-irradiation range.

10. the implantation angle adjustment mechanism includes a twist angle adjustment mechanism that adjusts a twist angle of the workpiece, supported by the support mechanism, at a center of the workpiece surface, around a rotation axis that is a normal line perpendicular to the workpiece surface; the twist angle adjustment mechanism adjusts the twist angle at the first implantation angle to a first twist angle, and adjusts the twist angle at the second implantation angle to a second twist angle different from the first twist angle; 10. An ion implantation apparatus according to claim 1.

11. 11. The ion implanter of claim 10, wherein a difference between the first twist angle and the second twist angle is greater than 0 degrees and less than or equal to 180 degrees.

12. 12. The ion implantation apparatus of claim 10, wherein when the processor executes steps (a) to (c) N times (N is a natural number greater than or equal to 2), the difference between the first twist angle and the second twist angle is equal for all N times.

13. 13. The ion implanter of claim 12, wherein N is an even number greater than or equal to 2 and less than or equal to 32.

14. 14. The ion implanter of claim 13, wherein the difference between the first twist angle and the second twist angle is 360 degrees divided by N.

15. (a) moving a workpiece adjusted to a first implantation angle with respect to an ion beam from a beam irradiation range in which the ion beam is irradiated onto at least a portion of the workpiece to a non-beam irradiation range adjacent to at least one end of the beam irradiation range in which the workpiece is not irradiated with the ion beam; (b) following the step (a), moving the workpiece at the first implantation angle within the non-beam irradiation range after the workpiece has moved from the beam irradiation range to the non-beam irradiation range, and reversing the direction of movement of the workpiece at an end of the non-beam irradiation range to move the workpiece toward the beam irradiation range; (c) initiating a change of the implantation angle of the object from the first implantation angle to a second implantation angle different from the first implantation angle while the object is moving within the beam non-irradiation range in the step (b), and completing the change to the second implantation angle while the step (b) is being performed; An ion implantation method comprising:

16. The ion implantation method according to claim 15 , wherein the non-beam irradiated area includes a first non-beam irradiated area adjacent to one end of the beam irradiated area and a second non-beam irradiated area adjacent to the other end of the beam irradiated area.

17. 17. The ion implantation method according to claim 15, wherein the step (b) is performed every time the object to be processed enters the beam irradiation range.

18. 17. The ion implantation method according to claim 15, wherein said step (b) is performed in said non-beam irradiation range, which said object enters after moving through said beam irradiation range a predetermined number of times.

19. 19. The ion implantation method according to claim 15, wherein in the step (b), the object is stopped at an end of the non-beam irradiated area for a predetermined stopping time.

20. 20. The ion implantation method according to claim 19, wherein the sum of the time during which the workpiece moves within the non-beam irradiation range toward an end of the non-beam irradiation range in step (b), the stop time, and the time during which the workpiece moves within the non-beam irradiation range toward the beam irradiation range in step (b) is equal to or greater than the time required to change the implantation angle of the workpiece from the first implantation angle to the second implantation angle.

21. 21. The ion implantation method according to claim 19, wherein in step (c), at least one of changing the implantation angle of the workpiece from the first implantation angle to the second implantation angle by an implantation angle adjustment mechanism capable of adjusting the implantation angle of the workpiece with respect to the ion beam, the workpiece being supported by a support mechanism that supports the workpiece to be irradiated with the ion beam, and completing the change is performed while a drive mechanism that reciprocates the support mechanism in a direction intersecting the ion beam is moving within the beam non-irradiation range.

Images